Check valve are pipeline valves which can automatically preventing reverse flow of working media. Working media can be water, no-aggressive liquids, steam, oi or oil products, air, gas. dimention:DN40-DN600 pressure:PN10/16 standard:DIN,ANSI,JIS,BS ect. High quality and No.1 after-sale service get our valves good markets nearly every parts of the world Acquirement of TUV CE0036&ISO9002 and SGS ISO9001 certificates makes Huihua set up a full set of Quality Managing System